My 510 came with a bunch of parts including 3 cylinder heads, 210, A87 and U60. I think the 210 was the stock L16 head from the car. The A87 and U60 are missing the valves and cams. The A87 looks like a clean head someone started to rebuild. The U60 looks heavily ported and was used at some. Are the valves available for this still? Is the U60 a good head for a L20B?

Looks to me like those heads have been flycut quite a bit when you look at the lettering which typically has a good amount of space between it and the headgasket surface. You should measure the thickness of the head to determine if too much has been removed which would require cam tower shims to make the head usable. You can still get valve and all associated valve train pieces.

"Lastnight the wife said oh boy when your dead you can't take nothing with you but your soul oh "Think"
- John Lennon

Valves readily available. What to build and what to use it on depends on your goals. You'd want to verify whatever head you want to put money into is sound, flat, and true. THEN, calculate the chamber size to plan out a compression ratio, all before spending money.

Easy to discuss stock heads. Once you come into a few heads that have had who-knows-what done to them over their lives, trust but verify.

Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson

Thanks for the info, I'm just trying to figure what I have and the condition. I measured all three heads last night. I would like to build a L20B with 9:5 - 10:1 compression, cam and side draft webers. I've done some reading and it sounds like if I use L18 pistons in a L20B with an open A87 open head I should be around 9:3, this would be fine if the block doesn't require boring. If I use flattop pistons from an L28 and bore the block 1mm I can get closer to 10:1with the open head. It all depends on the condition of the L20B when I get one.

I also read that the U60 head is rare but it just seems like there were not many made and it is basically a U67 head, is that correct? I would like to use this head since its been ported and polished.